Revenue - Contract Balances (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Contract Asset [Roll Forward]
Capitalized Contract Cost, Net, Beginning Balance	$ 32.0
Capitalized Contract Cost, Additions	4.5
Capitalized Contract Cost, Amortization	(5.7)
Capitalized Contract Cost, Net, Ending Balance	30.8
Contract with Customer, Liability, Current	1.5	$ 1.4
Contract with Customer, Liability, Noncurrent	27.8	$ 28.0
Fulfillment Costs [Member]
Contract Asset [Roll Forward]
Capitalized Contract Cost, Net, Beginning Balance	17.0
Capitalized Contract Cost, Additions	1.6
Capitalized Contract Cost, Amortization	(3.3)
Capitalized Contract Cost, Net, Ending Balance	15.3
Cost of Acquisition [Member]
Contract Asset [Roll Forward]
Capitalized Contract Cost, Net, Beginning Balance	15.0
Capitalized Contract Cost, Additions	2.9
Capitalized Contract Cost, Amortization	(2.4)
Capitalized Contract Cost, Net, Ending Balance	15.5
Entertainment and Communications [Member]
Contract Asset [Roll Forward]
Capitalized Contract Cost, Net, Beginning Balance	27.5
Capitalized Contract Cost, Additions	3.4
Capitalized Contract Cost, Amortization	(5.0)
Capitalized Contract Cost, Net, Ending Balance	25.9
Entertainment and Communications [Member] | Fulfillment Costs [Member]
Contract Asset [Roll Forward]
Capitalized Contract Cost, Net, Beginning Balance	14.5
Capitalized Contract Cost, Additions	0.9
Capitalized Contract Cost, Amortization	(2.9)
Capitalized Contract Cost, Net, Ending Balance	12.5
Entertainment and Communications [Member] | Cost of Acquisition [Member]
Contract Asset [Roll Forward]
Capitalized Contract Cost, Net, Beginning Balance	13.0
Capitalized Contract Cost, Additions	2.5
Capitalized Contract Cost, Amortization	(2.1)
Capitalized Contract Cost, Net, Ending Balance	13.4
IT Services and Hardware [Member]
Contract Asset [Roll Forward]
Capitalized Contract Cost, Net, Beginning Balance	4.5
Capitalized Contract Cost, Additions	1.1
Capitalized Contract Cost, Amortization	(0.7)
Capitalized Contract Cost, Net, Ending Balance	4.9
IT Services and Hardware [Member] | Fulfillment Costs [Member]
Contract Asset [Roll Forward]
Capitalized Contract Cost, Net, Beginning Balance	2.5
Capitalized Contract Cost, Additions	0.7
Capitalized Contract Cost, Amortization	(0.4)
Capitalized Contract Cost, Net, Ending Balance	2.8
IT Services and Hardware [Member] | Cost of Acquisition [Member]
Contract Asset [Roll Forward]
Capitalized Contract Cost, Net, Beginning Balance	2.0
Capitalized Contract Cost, Additions	0.4
Capitalized Contract Cost, Amortization	(0.3)
Capitalized Contract Cost, Net, Ending Balance	$ 2.1